I'm with a few of the others. WHY? I have been shooting TC's, custom smoke poles for 45 years and have never had the need or felt the need to pull a breech plug. I don't even pull the barrels from my self built long rifles when cleaning. I have one that I built in 1981 and I have shot thousands of rounds through it in competition and hunting and have never taken the barrel off of the stock to clean or other wise.
When I built a rifle, I fit the breech plugs with a LOT of force getting it timed (tang lined up with barrel flat) and never want it to come loose.
Can't see a reason to remove one, especially a TC. Clean the barrel good with what ever your choice of cleaner, pushing some out the nipple or touch hole until clean fluid is seen, wet patches, dry patches and then oiled patches. Good enough. I use the lubricant Break Free and have since I found it in 1986. I will clean an muzzleloader when finished and wipe the inside of the barrel and outside barrel, stock, lock and all with it. I may not touch it again until the next years season or shooting match. Never had one rust.
Mike